FormObject

Listing of Field Types »

FormObject[{"name1"type1,"name2"type2,}]

represents a form with fields having names namei that take data of type typei.

FormObject[{{"name1",label1}type1,}]

uses labeli as the label for the field named namei.

FormObject[{"name1"assoc1,,objj,}]

uses full specification associ for a field, and objj as part of the layout of the form.

Details and Options

  • FormObject[] displays in a notebook interface as a form with fields that can be filled in, either by entering text or using other controls.
  • FormObject can be used to specify the structure of a form in FormFunction.
  • When evaluated, FormObject[] is converted to FormObject[fields], in which each entry in fields has a full specification of the form "namei"->associ. The elements of the full specification associ include:
  • "Input"the raw input, if any, for the field (often a string)
    "Interpreter"the interpreter to be used for the field
    "Required"whether input is required for the field
    "Default"a default value, if any, for the field
    "Control"the type of control to provide for the field
    "AutoSubmitting"whether entering the field automatically submits the form
    "Disambiguation"whether to ask for disambiguation of interpretations
    "Label"a label to display for the field
    "Hint"hint to display inside an input field
    "Masked"whether to mask input given in an input field
    "Help"help to associate with the field
  • Setting[FormObject[]] gives an association of the form <|"name1"->val1,|>, where the vali are the values obtained by interpreting the "Input" element associated with each "namei" according to the "Interpreter" associated with the "namei".
  • If "Input" is missing, or "Interpreter" fails, then the value of "Value" is a Failure object.
  • FormObject[][<|"name1"->input1,|>] yields a FormObject[] in which the "Input" corresponding to each of the namei included has been replaced with inputi.
  • In FormObject[{,objj,}], the objj can be Delimiter, representing a horizontal delimiter.
  • They can also be expressions with heads Style, Row, Item, Text, ExpressionCell, and TextCell, as well as views and layout constructs such as TabView and Grid.
  • In FormObject[{"name1"->type1,}], the typei are used to give values for "Interpreter" in the full specification.
  • Possible forms of type specifications are:
  • "form"any form supported by Interpreter
    Restricted[],etc.any restricted form etc. supported by Interpreter
    Interpreter[]any complete Interpreter object
    tfunany function to be applied to the raw input
  • If only "namei" is given, without a rule giving typei, then the interpreter is assumed to be Identity, so that the value is exactly whatever is given as the corresponding "Input" element.
  • By default, the control used for each field is determined by the type of input specified. For type "String", a single line of input is by default expected on the web; typing "Text" yields a multiline text field.
  • Possible controls explicitly given as the value associated with "Control" include InputField, PopupMenu, Slider, and RadioButtonBar.
  • The specification "namei"->AutoSubmitting[typei] indicates that when the field associated with namei is entered, the whole form should automatically be submitted.
  • FormObject[AutoSubmitting[spec]] indicates that a form should automatically be submitted whenever any of its fields are entered.
  • Overall options for FormObject include:
  • AppearanceRulesAutomaticassociation giving overall appearance rules
    FormLayoutFunctionAutomaticfunction to generate final layout for the form
    PageThemeAutomaticoverall theme to use when the page is deployed
  • Typical elements in the setting for AppearanceRules include:
  • "Title"Noneoverall title for the form
    "Description"Nonedescription to include at the top of the form
    "RequiredFieldIndicator"Noneindicator to show required fields
    "SubmitLabel""Submit"text for the submit button of the form
    "AddLabel""+"text of the add button for repeating elements
    "DeleteLabel""-"text of the delete button
    "AddTooltip""Add"tooltip for the add button
    "DeleteTooltip""Remove"tooltip for the delete button
    "NextLabel""Next"text of the "next" button for multipage forms
    "ItemLayout""Horizontal"layout of field labels and messages
  • Possible settings for "ItemLayout" include "Horizontal", "Vertical", and "Inline".

Examples

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Basic Examples  (3)

Create an unfilled form:

Specify inputs for the form as strings:

Find the inputs that have been provided for the form:

The number has been parsed to an explicit number:

This input given for the second field cannot be parsed to a number, so a message is shown:

The setting contains a symbolic failure object:

Use different controls:

Scope  (17)

FormObject Structure  (1)

A valid FormObject evaluates to an object with an Association with all meta-information:

Form Submit  (1)

A form is submitted with subvalues:

When a form is submitted, data is stored in the second argument and input is inside the first argument:

Form metadata  (3)

You can extract form meta with subvalues:

You can extract "Help", "Control", "Interpreter", etc.:

"Control" gives you the default formatted controller:

Use "Failure" to get the failure:

If you do not specify a part to extract, the whole controller (with label and help) is returned:

You can extract AppearanceRules in the same way:

Use Setting to extract the cleaned data:

You can perform several submissions with partial data:

Using a form with defaults is considered valid even if not submitted:

Interpreter Specifications  (3)

Use rich Interpreter specifications:

A list can be used to create a menu:

Choices can be any expression:

Use a custom interpretation function:

Defaults  (1)

Specify a default for a field; fields that have a default are not required:

Use RuleDelayed to defer evaluation:

Input  (1)

Specify an initial value for a field:

Use RuleDelayed to force a fresh evaluation every time the form is rendered:

Controls  (2)

Different types have different controllers. Color pickers for "Color":

Or file pickers for file formats:

Checkboxes for "Boolean":

You can change the default controller:

Multiple choices support various types of controllers:

The control specification also accepts pure functions:

Label  (1)

Change the label for a field:

You can use RuleDelayed and return any expression:

Use None to remove the label:

Help  (1)

Define a help message:

You can use RuleDelayed and return any expression:

Hint  (1)

Use "Hint" to display a hint inside the controller:

Masked  (1)

Use "Masked" to hide the input in the controller:

Disambiguation  (1)

For strings that are interpreted from natural language in the Wolfram Cloud, sometimes results might be ambiguous:

Disambiguation is off for most types by default, but it can be easily activated:

Generalizations & Extensions  (1)

You can use a form inside an XMLTemplate; HTML code will be generated:

Extract metadata from a form and write a custom template:

Options  (2)

AppearanceRules  (1)

Write a custom title and description:

Use an image for branding:

Use an "ItemLayout" to change form fields' appearance:

FormLayoutFunction  (1)

A pure function can be specified to give a specific layout to a form:

Applications  (1)

Use FormObject to validate data:

Properties & Relations  (2)

You can use a FormObject as the first argument of APIFunction and FormFunction:

The single fields of a FormObject use Interpreter to transform the input in Wolfram Language expressions:

This is effectively the same as:

And the same as applying Interpreter directly:

Possible Issues  (1)

"Hint" and "Masked" are supported only by InputField:

"Hint" and "Masked" are ignored by other controllers:

Introduced in 2014
 (10.0)